Emi shield for molded packages

ABSTRACT

Electromagnetic interference (EMI) shielding structures for use inside an electronic system are provided, which allow access for mold compound or cables by using baffle-like features on the shield&#39;s sides and/or top, as well as methods for shielding components from EMI, or for containing EMI. The structures block external RF from sensitive components and reduce EMI emission from internal, RF generating components.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.16/041,357 filed on Jul. 20, 2018, which claims the benefit of U.S.Provisional Patent Application No. 62/535,699 filed on Jul. 21, 2017,the disclosure of which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD

Aspects of the present disclosure relate to the RF shielding ofcomponents in a molded package from Electro-Magnetic Interference (EMI).

BACKGROUND

System in Package (SIP) technology allows the integration into onepackage of the multiple die, devices and components needed to make up asystem. As more diverse technologies are used to manufacture die, SIPsare becoming useful for including and integrating all these various diesinto a system or subsystem. These systems often have a need tocommunicate with other systems or networks and are including componentsthat transmit and receive radio frequency (RF) signals (so-called“wireless components”).

In SIP molded packages, different types of devices and components may beassembled on a substrate prior to encapsulation. These devices andcomponents may be passive devices such as capacitors, inductors andresistors, and bare die or pre-packaged IC devices such as DRAM, CPU orother ICs. Typically, a molded SIP is encapsulated as part of the finalpackaging process. The encapsulating material, often referred to as amolding compound, can be a thermosetting plastic material with fillers,such as silica, in it. In this case, when the molding compound is heatedto a certain temperature, the molding compound melts and attains a verylow viscosity for a short period of time, and then it gels and hardens.It is important that while it is in liquid form it completely fill thepackage mold cavity. In the case of a SIP, the liquid form should notonly fill the mold cavity but also fill around and below the componentsthat have been previously mounted on a SIP substrate. In general, allthe passives and IC packages may be mounted on a SIP substrate such thateach of these devices and components have sufficient clearance above theSIP substrate for encapsulating material (hereinafter “encapsulant”) toflow between the bottom of the device/component and the substrate. Thisallows the encapsulant or molding compound to flow underneath thedevice/component and all around it to form a void free SIP package.Otherwise, the resulting SIP molded package may contain voids and airgaps, which may cause several problems, such as condensation of moistureand related degradation of a package, popping of the package duringsurface mount, cracking, corrosion and current leakage resulting fromcorrosion. Depending on the chosen encapsulant, voids may accumulatemoisture which will create unwanted electrical paths, thereby reducingthe expected life of a system. In system applications which are exposedto high pressure or vacuum environments, voids may further create apressure stabilization problem for the system.

The inclusion of components generating a radio frequency (RF) signal(e.g., a wireless communications component) in a SIP can present achallenge for the encapsulation process. In some wireless systems onprinted circuit boards (PCBs) that are not encapsulated, metal shields(or cans) are sometimes placed around the wireless component(s) toshield other components on the PCB from the RF signals. This radiofrequency emission shielding can help prevent electro-magneticinterference (EMI) with other components of the system. However, themetal shields (or cans) placed on the PCB would make it difficult toallow a molding compound to fill the gap between the metal EMI can andwireless components, and in particular, to do so without any voids orair gaps while sufficiently shielding of components of the system.

Accordingly, there remains a need for effective ways of providing RFshielding for components in a molded package from EMI.

SUMMARY

A metallic EMI shielding structure according to one or more embodimentsmay be used inside an electronic system or subsystem in a moldedpackage; the system may be a single chip or multichip package or asub-system, or a System-in-Package (SIP) device.

In addition to encapsulated packages, disclosed shield structures mayalso be used in packages that are not encapsulated but include cables orwires that are to be routed inside the shield structure from an outsidesource of radiation. In some embodiments, access for the moldingcompound or cables is enabled by creating baffle-like features on thesides and/or the top of the EMI structure. In some embodiments, thebaffle-like features can be created by cutting the metal that forms theEMI shield, but without removal of material. For instance, the cutportions may remain attached to the structure and pushed away from theremaining side portion to allow an opening in the side and/or top whilestill providing metal portions for shielding radiation which may beorthogonal, or nearly orthogonal, to the metal structure surface.

In some embodiments, an EMI shield, such as a metallic shield, may becreated without making any openings in the sides of the shieldstructure, by forming the sides of the structure in a special shape,such as a spiral or other labyrinth-like shape, to prevent EMI fromescaping or entering, while still allowing encapsulant to enter thestructure.

In some embodiments, additional mechanisms for reducing EMI are providedusing signal routing in a multi-layer substrate. This may include, forinstance, particular routing of signal from an RF device to an RF outputof a packaged device, or a device that is not packaged.

In some embodiments, a radio frequency (RF) radiation shield, maycomprise a plurality of walls formed of an RF radiation blockingmaterial, wherein at least one of said plurality of walls includes abaffle feature comprising an opening and a flap, and wherein saidopening is arranged to allow liquid molding material to flow into saidshield, and wherein said flap is arranged to substantially prevent RFelectro-magnetic radiation from at least one of entering and exitingsaid shield.

Regulatory bodies and agencies, like the Federal CommunicationsCommission (FCC), have regulations for controlling EMI emissions anddevice radiation. These regulations are in place to prevent unwantedsources of radiation from affecting the proper operation or function ofa circuit, components of a system, or signals within a circuit orsystem. That is, these regulations set forth guidelines to substantiallyprevent such unwanted radiations from impacting the normal operation ofsuch circuits, components of a system, or signals within a circuit orsystem by sufficiently reducing the radiation from such an unwantedradiation source to a point where it no longer affects the properoperation and/or function of a potentially affected circuit, componentsof a system, or signals within a circuit or system. As such,substantially preventing radiation from entering or exiting an elementmay be understood to entail sufficiently attenuating such radiation asto ensure proper operation and/or function in the appropriate device orsystem, for instance, in accordance with regulatory guidelines.

In some embodiments, a shield may comprise a plurality of walls formedof a metallic material, wherein at least one of said plurality of wallsincludes a baffle feature. Some embodiments include a shield having aplurality of walls formed of an RF radiation blocking material, whereinat least one of said plurality of walls includes means for allowingliquid molding material to flow into said shield and for substantiallypreventing electro-magnetic radiation from at least one of entering andexiting said shield.

In some embodiments, a radio frequency (RF) radiation shield is providedhaving at least one wall formed of an RF radiation blocking material,wherein a first portion of said wall overlaps a second portion of saidwas such that liquid molding material can flow into said shield, andwherein said wall is arranged to substantially prevent electro-magneticradiation from at least one of entering and exiting said shield, andwherein said wall may be arranged in a spiral shape.

In other embodiments, an RF shield is provided for an RF generatingcomponent mounted on a substrate for an integrated circuit device, wheresaid device is to be encapsulated as part of its packaging, having ametallic container mounted over said RF generating component and havingopenings on the top and at least one side to allow liquid encapsulant toflow into said container and fully encapsulate said RF generatingcomponent when said device is being encapsulated, wherein said openingsallow encapsulant to enter and fill up said container whilesubstantially reducing electro-magnetic radiation from said RFgenerating component from leaving said container. In some embodiments,there is at least one additional opening for operatively connecting saidRF generating component to other components on said substrate.

In certain aspects, the integrated circuit device may be a SIP. Further,each opening may have a flap associated with it located inside oroutside of said container that substantially prevents or minimizeselectro-magnetic radiation emissions from leaving said container whileallowing encapsulate to flow around and fully encapsulate said RFcomponent in a SIP.

In other aspects, an RF shield for an RF generating component mounted ona substrate for a device is provided. In some embodiments, the device isto be encapsulated as part of its packaging. The shield may comprise,for instance, a metallic container mounted over said RF generatingcomponent and having openings on the top and at least one side to allowliquid encapsulant to flow into said container and fully encapsulatesaid RF generating component when said device is being encapsulated,wherein said openings are partially blocked by a flap spaced from andassociated with said wall or top of said container to allow encapsulantto enter and fill up the container while substantially reducingelectro-magnetic radiation from said RF generating component fromleaving said container. Some embodiments include a labyrinth shapedmetallic container having one side exterior opening to allow liquidencapsulant to flow into said container and fully encapsulate said RFgenerating component located in the center of said labyrinth when saiddevice is being encapsulated. And may include openings on one side whilefully covering said RF generating component and allowing aninterconnection with other components on said substrate, wherein saidopening is partially blocked by a baffle member spaced from andassociated with said container.

In some embodiments, an RF shield is provided for protecting an RFsensitive component mounted on a substrate for a device, where saiddevice is to be encapsulated as part of its packaging, and includes ametallic container mounted over said RF sensitive component and hasopenings on the top and sides to allow liquid encapsulant to flow intosaid container and fully encapsulate said RF sensitive component whensaid device is being encapsulated, wherein said openings allowencapsulant to enter and fill up the container while substantiallypreventing electro-magnetic radiation from entering said container.

In some embodiments, a packaged integrated circuit device encapsulatedusing liquid encapsulant during packaging is provided. The device maycomprise a substrate; and an electromagnetic radiation blocking elementmounted over a radiation-generating component on the substrate. Incertain aspects, the radiation blocking element comprises an opening onthe top of the element and at least one side opening, and the radiationblocking element is filled with encapsulant.

According to some embodiments, a method for encapsulating an integratedcircuit device using liquid encapsulant during packaging is provided.The method may comprise mounting an electromagnetic radiation blockingelement over a radiation-generating component on a substrate for theintegrated circuit device, wherein said radiation blocking elementcomprises an opening on the top of the element and at least one sideopening. The method may further comprise encapsulating the integratedcircuit with liquid encapsulant, wherein the encapsulating comprisesfilling the radiation blocking element with the encapsulant. In certainaspects, at least one of the openings comprises a baffle feature.

In some embodiments, a method for protecting components mounted on amultilayer substrate of an integrated circuit from electromagneticinterference (EMI) from an RF generating component mounted on saidsubstrate, are provided by creating an RF signal path from said RFgenerating component that passes through said multiple layers of saidsubstrate to an external RF output for said integrated circuit, andshielding said RF signal path through said multiple layers usinggrounded vias and grounded conductive surfaces surrounding said RFsignal path for multiple pluralities of said multiple layers.Additionally, a metallic container may be placed on said substrate oversaid RF generating component. Further, the RF output of said RFgenerating component may be located directly above the external RFoutput for said integrated circuit.

Some embodiments provide a method for substantially preventingelectromagnetic emissions from an RF signal path between the RF outputof an RF generating component mounted on a multiple layer substrate ofan integrated circuit and the external RF output of said integratedcircuit, by forming ground traces around the interface of said RF outputof said RF generating component with the interconnection pad on the topsurface of said substrate, generating an RF signal path from saidinterconnection pad to multiple internal connection layers using vias,shielding said RF signal path from said interconnection pad through aplurality of said multiple layers to each of said internal connectionlayers using grounded vias and grounded conductive surfaces surroundingsaid RF signal path for each of multiple pluralities of said multiplelayers, generating an RF signal path from a final internal connectionlayer to external RF output of said integrated circuit using a via, andshielding said RF signal path from said final internal connection layerto said RF output using grounded vias and grounded conductive surfacesthat are grounded surrounding said RF signal path and said external RFoutput.

Some embodiments include an integrated circuit having a multi-layersubstrate, and an RF generating component mounted on said substrate,wherein said substrate comprises an external RF output and means forshielding an RF signal path between said RF generating component andsaid RF output.

According to some embodiments, an integrated circuit is provide whichhas a component located on the top surface of a multi-layer substrateand contains a shielded RF transmission path through the multiple layersof said substrate between an external signal connector for the circuitand a signal terminal of the component. This may comprise, for instance,at least one via for making an electrical connection between a signalconnector or an electrically conductive trace located on one layer ofthe multilayer substrate and a signal connector or an electricallyconductive trace located on a different layer of the multilayersubstrate, and a plurality of electrically grounded vias surroundingeach of the at least one via and connected to a plurality ofelectrically grounded conductive traces surrounding but isolated fromeach of the electrically conductive traces on each layer of the multiplelayers. In certain aspects, the electrically grounded conductive tracesare located on the same layer as each of the electrically conductivetraces, and the layer above and below the layer containing each of theelectrically conductive traces.

These and other features of the present disclosure will become apparentto those skilled in the art from the following detailed description ofthe disclosure, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C depict structures used for shielding EMI radiation from anRF device in a SIP according to some embodiments.

FIGS. 2A and 2B depict a baffle feature according to some embodiments.

FIGS. 3A-3C depict processes of manufacturing a structure used forshielding EMI radiation from an RF device in a SIP according to someembodiments.

FIG. 4 depicts a side view of a SIP with an EMI shield according to someembodiments.

FIGS. 5A-5D depict a system according to some embodiments.

FIG. 5E depicts a method of connecting the output of an RF device to anexternal output connector (e.g., ball or pin) of the SIP withsurrounding shielding in the substrate according to some embodiments.

FIGS. 6A and 6B depict a system according to some embodiments.

FIG. 6C depicts a method of connecting the output of an RF device to anexternal output connector (e.g., ball or pin) of the SIP withsurrounding shielding in the substrate according to some embodiments.

FIG. 7 depicts a method of forming a packaged integrated circuitaccording to some embodiments.

DETAILED DESCRIPTION

Wireless components in a system may require shielding to prevent strayradiation from the radio frequency (RF) generating (e.g., wirelesscommunications) components from affecting nearby components or systems.Accordingly, some embodiments of the present disclosure relate toproviding RF shielding structures for devices, such as wireless devices,that are suitable for use in encapsulated systems and products, such asin SIPs. In some embodiments, the molding compound or encapsulantmaterial may include a resin or plastic material, thermosetting orthermoplastic resin, as well as ceramic materials. The molding compoundmay flow in liquid form around and through the RF shielding structuresof some embodiments, enabling effective molding. In certain aspects, theRF shields may employ a metallic structure (or container) covering theRF generating component to keep any unintended RF in the structure withthe RF generating component, or alternatively a metallic structure maybe placed over a low noise component to shield this component fromexternal RF radiation. In addition to metallic structures, the shieldmay be formed of other materials capable of blocking RF radiation. Insome embodiments, the wireless components in any system may requireshielding to prevent stray EMI radiation from the RF generatingcomponent from affecting nearby components or systems.

In particular, structures that enable the effective flow of a moldingcompound while providing sufficient EMI reduction are important as RFdevices continue to increase in operational frequency. That is, atincreased frequencies, even relatively “small” openings to allow theflow of molding compound can be “large” in terms of allowing RFradiation to enter or exit. By way of example, at 300 GHz, aquarter-wavelength is only 0.25 mm.

A System in Package device (SIP) may contain an RF device within it thatis prone to emit stray EMI radiations. Such radiations are undesirableas they may interfere with the function of adjacent devices of nearbysystems or other components in the SIP. Further, the function of the RFdevice or other devices in a SIP may be compromised by RF radiationcoming from outside of the RF device or the SIP. EMI emissions orradiations are strictly controlled by regulations such as those from theFCC.

FIGS. 1A-1C depict RF or EMI shielding structures according to someembodiments of the present disclosure. For instance, FIG. 1A depicts anRF shielding structure 100 with side walls 101 and top wall 102. The RFshielding structure 100 can be used to shield other devices from RFradiation, as well as to protect a device from RF radiation due to otherdevices or external sources. In an embodiment, the RF structure 100 isin the shape of a rectangular can and sized to fit over and around an RFgenerating chip or component, for instance, an RF device containedwithin an SIP. While the structure is depicted in a rectangularconfiguration, it may also, for example, but not limited to, be round,contain rounded walls, and include more or less than four walls,according to some embodiments. Additionally, for certain applications,the top 102 may be excluded. In the example of FIG. 1A, the RF shieldingstructure 100 is provided with apertures (e.g., holes or slots) to allowmolding compound to enter and air to be vented out of the RF shieldingstructure 100.

According to some embodiments, the apertures are provided as bafflefeatures 124 or 104 in the side walls 101 or top 102, respectively,which comprise an opening 103 and a flap 108 made to allow moldingcompound or encapsulant to enter the RF shielding structure 100 duringencapsulation, while minimizing the RF radiation passing through theopening. In some aspects, the baffled opening 103 can allow the moldcompound to enter and fill the RF shielding structure 100 withoutforming any voids or air gaps. Accordingly, the RF shielding structure100 can enable effective molding while reducing the chances ofsignificant radiation escaping (or entering) through the baffled opening103, thus, preventing potential interference with other devices. In anembodiment, the baffle features 124 may be positioned on the structuresuch that they are approximately 90 degrees to the incident radiationfor maximum effectiveness in blocking and/or absorption.

In some embodiments, the encapsulating material (molding compound) is athermosetting plastic material with fillers, such as silica, in it. Inthis example, when the molding compound or encapsulant is heated to acertain temperature it melts, attains a very low viscosity for a shortperiod of time, and then it gels and hardens. While it is in liquid formit completely fills the package mold cavity. In the case of a SIP, themold compound or encapsulant should not only fill the mold cavity butalso fill around and below the components that have been previouslymounted on a SIP substrate. In some embodiments, all the components maybe mounted on a SIP substrate such that each of these components havesufficient clearance above the SIP substrate for encapsulant to flowbetween the bottom of the component and the substrate. This allows theencapsulant to flow underneath the component and all around it to form avoid free SIP package. In certain aspects, the shielding structuresdepicted in FIGS. 1A-1C do not interfere with this process.

As illustrated in FIG. 1A, baffle features 104 with flaps are includedon the top 102 of structure 100 to allow the mold compound orencapsulant to flow through it also. The features 104 can minimize, oreven eliminate, voids in the mold compound within the RF shieldingstructure 100. In certain aspects, the RF shielding structure's materialis specifically chosen to minimize the amount of RF radiation that isemitted either by absorbing the energy or by containing it, such as ametal. Such RF-blocking materials can include, for example, not onlymetals, but other electrically conductive materials.

FIG. 1B depicts a structure 110 used for shielding EMI radiations from aRF device according to some embodiments. RF shielding structure 110 maybe made, for instance, of metal. In this embodiment, it comprises aspiral-shaped sheet of metal 111 that is formed around the RF device ina way that totally encompasses the perimeter of the RF device and has anover lapping section 112. That is, a first portion of a wall overlaps asecond portion of the wall. The resulting shape forms an RF shieldingstructure 110 with an overlap, which comprises an opening 114 forencapsulant to fill in the space 113 between the RF device and thestructure 110.

In some embodiments, the spiral-shaped wall 111 of FIG. 1B may also becovered with a flat piece of material 120, such as metal, as shown inFIG. 1C. In this example, top 120 may include baffle features 124 in thelayer 122 to allow trapped air to escape and encapsulant to enter andfill up the space as it displaces the air. The spiral shape allowsencapsulant to enter but blocks EMI radiation from exiting (or entering)the structure. In some instances, the flat piece 120, which is used as alid as shown in FIG. 1C, may not be necessary if only the other circuitsor components on the SIP substrate are to be protected from RF signals.If the flat piece 120 is eliminated, it could allow for even better flowof the mold compound to eliminate encapsulant voids in it, but couldstill, protect other circuits from RF generated by an RF device. Forinstance, by blocking radiation in a laterally outward direction fromthe device.

According to some embodiments, the baffle feature 124, with opening 103and flap 108, may be formed in different configurations, for instance,as illustrated in FIGS. 2A and 2B. For example, FIG. 2A illustratesbaffle feature 124 with the flap 108 connected to the opening 103 via aconnecting part 202 configured at an angle smaller than a right angle.In another example, FIG. 2B illustrates feature 124 with the flap 108connected to the opening 103 via a connecting part 204 configured at aright angle. In an embodiment, the baffle features 124 may be formed oneither surface of the flat piece of metal 122. Additionally, as shown inthese figures, the flap portion may extend into, or outward from, the RFshielding structure.

FIG. 3A depicts a process 300 of manufacturing the RF structure 100 asdescribed in FIG. 1A, according to some embodiments. In step 310, thewalls of shield 100 are formed, for instance, by punching out the shapeof the shield from a metal sheet. The walls may also be formed bycutting and wrapping metal sheets to form the side walls and top wallsof the structure. In step 320, baffle features, such as feature 124 arecut into one or more of the walls. This cutting may include, forinstance, a punching process. A similar process may be used to form thetop 120 shown in FIG. 1C. In some embodiments, baffle features are madeby creating one or more cut outs in a flat piece of metal while leavingthe flap attached to each cut out. This results in the baffled cut outs124 in the flat piece of metal as described in connection with FIG.1A-1C. Specifically, the flat piece of metal can be cut to form a flap.The cut portion can then be pushed away from the flat piece of metal toallow an opening while the flap remains attached. In some embodiments,steps 310 and 320 may be performed in a single step. For instance, usinga punching mechanism with a non-uniform surface that not only createsthe shape of the shield structure, but also cuts out the baffle feature.

FIG. 3B depicts another process 330 of manufacturing the RF structure100 as described in FIG. 1B, according to some embodiments. In step 340,one or more baffle features, such as feature 124, may be cut into asheet of material, such as a metal sheet. In step 350, a strip ofmaterial may be cut from the portion of the sheet comprising the bafflefeatures. In step 360, the strip may be arranged to form the walls 101illustrated in FIG. 1A. The strip may also be arranged in aspiral-shaped configuration as shown in FIG. 1B. In step 370, a top wallportion may be attached. This top wall may include one or more bafflefeatures as well.

FIG. 3C depicts a process 380 of manufacturing the RF structure 110 asdescribed in FIG. 1B, according to some embodiments. In step 381, asheet of metal is wrapped to form a metal structure in a spiral shapeconfigured to encompass the perimeter of an RF device. The metalstructure comprises an opening sufficiently large enough for encapsulantto fill in a space between the RF device and the metal structure. Instep 382, a top layer 120 is added. According to some embodiments, thetop layer may include one or more baffle features.

FIG. 4 depicts a side view of an RF shielding structure in a moldedpackage 400, according to some embodiments. In this example, structure401 has a baffled opening 402 with a flap. For instance, structure 401may correspond to the device of FIG. 1A. In this arrangement, the RFradiation is further reduced. That is, a louvered slot EMI shieldingstructure 401 which comprises a separate flap 402 at the opening orslot, effectively reduces 403 EMI radiation in accordance with theteachings of the present disclosure. As shown in FIG. 4, moldingcompound 405 fills the gap under shielding structure 401.

In certain aspects, a shield for an EMI or RF generating component ismounted on a substrate for an integrated circuit device, where saiddevice is to be encapsulated as part of its packaging, that includes ametallic container mounted over said EMI or RF generating component andhaving openings on the top and at least one side to allow liquidencapsulant to flow into said container and fully encapsulate said EMIor RF generating component when said device is being encapsulated,wherein said openings allow encapsulant to enter and fill up saidcontainer while substantially reducing electro-magnetic radiation fromsaid EMI or RF generating component from leaving said container.

FIGS. 5A-D depict an arrangement for reducing unwanted RF energy whilethe output RF from the wireless transmitter is conducted to the outputof the system of which it is a part. FIG. 5A is a side view of a portionof a section of a system 500. In this example, the system 500 comprisesa six layer PCB with layers 501-506, a RF transmitting device 510,signal traces 518, 511, 522, 524, 514, 526 and external connections suchas 507, 508, 509. While illustrated with six layers, in some instances,more or less layers may be used. As also shown in FIG. 5B, in thisexample, there is a component generating an RF signal 510. The RF signalis connected from the RF generator 510 through one of its externalconnections 511 to the external connection 508 of the system 500.According to some embodiments, RF generator 510 may further include anRF shield as illustrated in FIGS. 1A-1C.

To minimize the RF radiation emitted through the PCB, the conductivetraces 512, 514 between the source 511 and the system output connector508, are shielded by connecting together a series of grounded conductivetraces 522, 524, 526. The RF signal path traces are connected from thetop layer 501 of the PCB to the third layer 503 with a via 513 andfinally from the third layer to the external connection 508 through avia 515. In the same way, the grounded conductive traces which areabove, below and on each side of the RF signal path trace 514 areconnected from layer one 501 to layer two 502 and layer three 503 andlayer four by vias 525. Finally the grounded conductive traces areconnected to the surrounding external ground connections 507, 509 byvias 527, 528.

FIG. 5B depicts a top view of a portion the system of FIG. 5A,illustrating the RF signal path 512 and ground traces 533 for the RFoutput signal from the appropriate connectors such as 511, 521 of RFtransmitting device 510. In this example, the RF signal path begins withthe RF output connector 511 of the RF generating component 510 and isconnected to a via 513 using RF conductive signal trace 512. Theassociated ground connectors 521 are electrically connected with aconductive trace 533 to each other and to a grounded via 523. The RFsignal path and ground are connected to the appropriate layers using thevias 513 and 523, respectively.

FIG. 5C depicts a portion of the system in FIG. 5A in a top view of theappropriate conductive traces on level three 503 of the PCB. In thisexample, the RF signal trace 526 is electrically connected to two vias:(1) from layer one 513; and (2) to layer six 515. The ground traces havemultiple traces: (1) from layer one 523; (2) to layer six 527 and 528;and (3) to layers two and layer four 525. Although layers two 502 andfour 504 are not depicted in the illustration, it should be noted thateach can have metal traces which cover the area between the groundtraces on level three 542 and shield the signal trace 526 on the thirdlayer 503 from above and below.

FIG. 5D depicts layer six 506 of the PCB. Specifically it shows theexternal connectors for the RF path signal 567 and grounds 562-566. Inthis example, the ground connectors are connected by a conductive trace561 and to the appropriate other levels by vias described in FIG. 5Band/or 5C.

Thus some embodiments provide a method for protecting components mountedon a multilayer substrate of an integrated circuit from electromagneticinterference from an RF generating component mounted on said substrate,by creating an RF signal path from said RF generating component thatpasses through said multiple layers of said substrate to an external RFoutput for said integrated circuit, and shielding said RF signal paththrough said multiple layers using grounded vias and grounded conductivesurfaces surrounding said RF signal path for multiple pluralities ofsaid multiple layers. Additionally, a metallic container may be placedon said substrate over said RF generating component. Further, the RFoutput of said RF generating component may be located directly above theexternal RF output for said integrated circuit.

And other embodiments provide an integrated circuit having a componentlocated on the top surface of a multi-layer substrate and containing ashielded signal or RF transmission path through the multiple layers ofsaid substrate between an external signal connector for said circuit anda signal terminal of said component, having at least one via for makingan electrical connection between a signal connector or an electricallyconductive trace located on one layer of said multilayer substrate and asignal connector or an electrically conductive trace located on adifferent layer of said multilayer substrate, and a plurality ofelectrically grounded vias surrounding each of said at least one via andconnected to a plurality of electrically grounded conductive tracessurrounding but isolated from each of said electrically conductivetraces on each layer of the multiple layers, wherein said electricallygrounded conductive traces are located on the same layer as each of saidelectrically conductive traces, and the layer above and below the layercontaining each of said electrically conductive traces. This shieldedpath may be used to prevent the signal on the path from escaping fromthe path, or may be used to prevent external signals from outside thepath affecting or interfering with the signal on the path.

FIG. 5E depicts a process 580 for substantially preventingelectromagnetic emissions from an RF signal path between the RF outputof an RF generating component mounted on a multiple layer substrate ofan integrated circuit and the external RF output of the integratedcircuit, according to some embodiments. Process 580 may create, forexample, a system as illustrated in FIGS. 5A-D.

According to some embodiments, process 580 may begin with step 582, byforming ground traces around the interface of the RF output of the RFgenerating component with the interconnection pad on the top surface ofthe substrate. This may be followed by step 584, creating an RF signalpath from the interconnection pad through multiple internal connectionlayers using vias. Accordingly, the RF signal path is shielded startingfrom the interconnection pad through a plurality of the multiple layersto each of the internal connection layers. Grounded vias and groundedconductive surfaces are used to surround and shield the RF signal pathfor each of multiple pluralities of the multiple layers. In step 586, anRF signal path is created from a final internal connection layer toexternal RF output of the integrated circuit using a via. Accordingly,the RF signal path is shielded starting from the final internalconnection layer to the RF output. Grounded vias and grounded conductivesurfaces are used to surround and shield the RF signal path and theexternal RF output.

FIGS. 6A and 6B depict an arrangement for reducing the unwanted RFenergy when the output RF from the wireless transmitter is conducted tothe RF output of the SIP of which it is a part, in accordance with someembodiments.

For instance, FIG. 6A depicts a section of a system 600 having a sixlayer PCB 601, external connectors such as 608, and an RF generatingdevice 603 with connectors such as 604. In some embodiments, it may beencapsulated with material 602 depending on its application. In thisexample, the connection between the RF output connector 604 on the RFgenerating device 603 is directly above and connected to the systemoutput connector 608 using a via 605 through all of the layers 601.Surrounding the RF signal via 605 are several ground vias 607 andothers, for instance as described with respect to FIGS. 5A-5D. Thesevias further isolate the RF output from the rest of the circuits on thePCB. On each layer of the PCB 601 are conductive rings 624 around the RFsignal via 605 and a larger ring 622 around it connecting all of theground vias 607 and others. In certain aspects, this arrangementminimizes the length the RF signal must go between the source and outputof the system. Surrounding the RF ball 608 there may also be a ring ofballs grounded, for instance, as discussed with respect to FIGS. 5A-5D.According to certain aspects, when additional traces cannot be avoidedthey are included with a direct path to a through via and in a manner toavoid bends and kinks.

FIG. 6B depicts a portion of system 600 from FIG. 6A in a top view 620of the layers of the PCB 601. In this example, only the vias 605, 607used in the layout 622, and their traces on each layer 624 and 609, aredepicted. According to some embodiments, the grounding ring 609 isolatesthe RF signal via 605 from the rest of the signal traces on each of thelayers of the PCB 601. Finally the addition of grounding balls, like562, 563, 564, 565 and the metal trace 561 connecting the groundingballs in a similar manner to that shown in FIG. 5D, further isolates theRF signal from the remainder of the system.

FIG. 6C depicts a process 650 of one embodiment of the presentdisclosure for protecting components mounted on a multilayer substrateof an integrated circuit from electromagnetic interference from an RFgenerating component mounted on the substrate, as illustrated in FIGS.6A and 6B. The process 650 may begin in step 652, by creating an RFsignal path from the output of said RF generating component locatedabove an external RF output that passes through the multiple layers ofthe substrate to the external RF output for said integrated circuit. Instep 654, the RF component 603 is operated and the RF signal paththrough said multiple layers is shielded using grounded vias andgrounded conductive surfaces surrounding said RF signal path formultiple pluralities of said multiple layers.

FIG. 7 depicts a process 700 for manufacturing a molded integratedcircuit. This may be, for instance, a SIP device. In step 710, an RFshield, such as a shield depicted in FIGS. 1A-1C, is placed over an RFcomponent of an integrated circuit. In step 720, a molding operation isperformed on the integrated circuit such that molding compound flowsinto the RF shield.

While various embodiments of the present disclosure are describedherein, it should be understood that they have been presented by way ofexample only, and not limitation. Thus, the breadth and scope of thepresent disclosure should not be limited by any of the above-describedexemplary embodiments. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by thedisclosure unless otherwise indicated herein or otherwise clearlycontradicted by context.

Additionally, while the processes described above and illustrated in thedrawings are shown as a sequence of steps, this was done solely for thesake of illustration. Accordingly, it is contemplated that some stepsmay be added, some steps may be omitted, the order of the steps may bere-arranged, and some steps may be performed in parallel.

What is claimed is:
 1. A packaged integrated circuit device, comprising:a multi-layer substrate comprising a top surface and a bottom surface; aplurality of components mounted on said top surface of said substrate; aradiation-generating component mounted on said top surface of saidsubstrate, wherein said radiation-generating component comprises anoutput; a signal path that passes through said substrate between saidoutput of said radiation-generating component and an output connectorfor external connection on said bottom surface of said substrate; andmeans for shielding said signal path within said substrate, wherein saidtop surface of said multi-layer substrate, said plurality of components,said radiation-generating component, and said shielding means are allcontained within the packaged integrated circuit device.
 2. The packagedintegrated circuit device of claim 1, wherein at least one of saidplurality of components and said radiation-generating component areoperatively interconnected using vias and conductive traces located onindividual layers of said multi-layer substrate.
 3. The packagedintegrated circuit device of claim 1, wherein said signal path iscomprised of an interconnection of an output of saidradiation-generating component with a signal interconnection pad on saidtop surface of said substrate and having ground traces formed aroundsaid interconnection and spaced apart from said interconnection, and aplurality of vias interconnected with said signal interconnection padand each interconnected using conductive traces on each layer of saidmulti-layer substrate and interconnected with said output connector forexternal connection, and wherein said means for shielding comprisesgrounded vias interconnected with grounded conductive traces surroundingand spaced apart from said signal path vias and traces for each of saidmultiple layers of said multi-layer substrate.
 4. The packagedintegrated circuit device of claim 1, wherein said packaged integratedcircuit device is a system-in-package (SiP).
 5. The packaged integratedcircuit device of claim 1, wherein said signal path comprises onevertical via passing through each layer of said multi-layer substratebetween said radiation-generating component and said output connector.6. The packaged integrated circuit device of claim 1, wherein saidmulti-layer substrate comprises four or more layers.
 7. The packagedintegrated circuit device of claim 1, wherein said multi-layer substratecomprises six or more layers.
 8. A packaged integrated circuit device,comprising: a substrate comprising multiple layers; and at least oneradio frequency (RF) component mounted on said substrate, wherein saidsubstrate comprises an RF output for external connection and an RFshield within said substrate, and wherein said RF shield surrounds an RFsignal path between said RF component and said RF output.
 9. Thepackaged integrated circuit device of claim 8, wherein said RF signalpath comprises at least one via, and wherein said RF shield comprisesgrounded vias and grounded conductive surfaces surrounding said at leastone signal path via for each layer of said multi-layer substrate. 10.The packaged integrated circuit device of claim 8, wherein said packagedintegrated circuit device is a system-in-package (SiP).
 11. The packagedintegrated circuit device of claim 8, wherein said signal path comprisesone vertical via passing through each layer of said multi-layersubstrate between said RF component and said RF output, and wherein saidRF shield comprises grounded vias and grounded conductive surfacessurrounding said one signal path via for each of said multiple layers ofsaid multi-layer substrate.
 12. The packaged integrated circuit deviceof claim 8, wherein said RF component is mounted on an upper surface ofsaid substrate and said RF output is located on a lower surface of saidsubstrate.
 13. The packaged integrated circuit device of claim 8,further comprising a plurality of components, wherein said plurality ofcomponents and said RF component are operatively interconnected usingvias and conductive traces located on individual layers of saidmulti-layer substrate.
 14. The packaged integrated circuit device ofclaim 8, further comprising a metallic container located over said RFcomponent.
 15. The packaged integrated circuit device of claim 8,wherein said substrate comprises four or more layers.
 16. The packagedintegrated circuit device of claim 8, wherein said substrate comprisessix or more layers.
 17. The packaged integrated circuit device of claim8, wherein said RF component is a wireless transmitter.
 18. A method forprotecting components in a packaged integrated circuit device fromelectromagnetic interference from an RF generating component mounted ona substrate with said components, comprising: creating an RF signal pathfrom said RF generating component that passes through multiple layers ofsaid substrate to an external RF output for said integrated circuitdevice, and shielding said RF signal path through said multiple layersusing grounded vias and grounded conductive surfaces surrounding said RFsignal path for each of said multiple layers.
 19. The method of claim18, wherein creating said RF signal path comprises creating one verticalvia passing through each layer of said substrate between said RFgenerating component and said external RF output.
 20. The method ofclaim 18, further comprising: placing a metallic container on saidsubstrate over said RF generating component prior to packaging saiddevice.